The Red List of Ecosystems: assessing the extinction risk of ecosystems

Most people are familiar with the concept of extinction, and are aware of the IUCN Red List of Threatened Species (RLTS), a classification of the Earth’s organisms into different categories based on their population levels and dangers facing their survival. RLTS was founded in 1964, and was initially considered the best way forward in global conservation. Unfortunately, the plan of documenting all living organisms of the planet has proven cumbersome and slow, and currently the project’s aim is to classify 160 000 species by 2020. That accumulates to only 8% of all species currently known to exist. The task seems daunting and never-ending. Although certain individual species have been brought back from the brink of extinction thanks to having their “specs” measured, the RLTS has been unable to curb or stop the increasing population decline of countless species.

As a list of individual species has proved inadequate to counter biodiversity loss, the next step forward was taken during the 2000s with the formation of the Red List of Ecosystems (RLE). The idea behind this is fairly simple; each ecosystem is compared to a set of criteria, assessed in terms of its risk of collapsing (meaning the disintegration of its functioning leading to collapses in biodiversity), and finally categorized according to its current functioning and stability. It is in fact a hazard assessment for the extinction risk of individual ecosystems. The criteria used in evaluating each ecosystem includes assessing how much of their original flora and fauna have been converted, degraded or destroyed, and how much of their original size remains.

Classification is pretty similar to that of the RLTS: ecosystems can currently be at no risk of collapse (least concern), at three different levels of being threatened (vulnerable, endangered, or critically endangered), or they may already be approaching a final state of degradation (collapse). We may also have too little information (data deficient) to make an assessment, or their health may not have been appraised yet (not evaluated).

Once classified, appropriate planning and management measures can be taken to enhance or restore ecosystem functionality, which often also improves the stability of societies living within the influence of these ecosystems. For example, wetland restoration benefits societies by providing cleaner water for household use and by preventing or lessening flood and drought damage.

The RLE is an important tool for communicating between ecologists, decision-makers, and developers. The system provides robust and straightforward guidelines that are applicable to all types of ecosystems around the globe. One noteworthy goal of the IUCN is to assess and showcase ecosystems that are currently doing well, not just those that are at risk of collapse. Such well-to-do ecosystems are important, so as to pinpoint the reasons and most efficient management practices that have led to their current health.

However, improvement is always necessary. One such avenue for improvement lies in getting nations to collaborate together in conserving ecosystems crossing borders. This would greatly improve the connectivity of landscapes, improving habitats for migratory species, species with large habitat area requirements etc. But when used jointly with other conservation measures, such as the assessment of ecosystem services, spatial management planning, and the IUCN RLTS, this new method seems very promising. Currently the aim of the IUCN is to have all the Earth’s ecosystems assessed by 2025. This will be carried out at the national and regional level, and results will be freely accessible in an online database.